A huge market exists for hard disk drives for mass-market computer systems such as servers, desktop computers, laptop computers, and mobile computers (e.g., mobile devices, PDAs, cell phones, etc.). To be competitive in this market, a hard disk drive should be relatively inexpensive, and should accordingly embody a design that is adapted for low-cost mass production. Further, there exists substantial competitive pressure to continually develop hard disk drives that have increasingly higher storage capacity, that provide for faster access to data, and at the same time conform to decreasingly smaller exterior sizes and shapes often referred to as “form factors.” Satisfying these competing constraints of low-cost, small size, high capacity, and rapid access requires innovation in each of the numerous components and methods of assembly. Typically, the main assembly components of a hard disk drive are a head disk assembly (“HDA”) and a printed circuit board assembly (“PCBA”).
The HDA typically includes at least one magnetic disk (“disk”), a spindle motor for rotating the disk, and a head stack assembly (“HSA”) that includes a head with at least one transducer for reading and writing data. The HSA is controllably positioned by a servo system in order to read or write information from or to particular tracks on the disk. The typical HSA has three primary portions: (1) an actuator assembly that moves in response to the servo control system; (2) a head gimbal assembly (“HGA”) that extends from the actuator assembly and biases the head toward the disk; and (3) a flex cable assembly that provides an electrical interconnect with minimal constraint on movement. The PCBA typically includes signals for processing signals and controlling operations. Within the HDA, the spindle motor rotates the disk or disks, which are the media to and from which the data signals are transmitted via the head of the HGA. Further, many hard disk drive include more than one disk and there may be multiple HGAs with read/write heads for reading from or writing to each disk surface. A typical disk drive may have an array of HGAs with read/write heads arranged in opposing pairs
For disk drive manufacturing, the HSA may be shipped together with a shipping comb that separates and protects the heads of the HGAs prior to the integration of the HSA into the HDA to assemble the disk drive. In the manufacture of a disk drive with a ramp design, the HGAs need to be loaded or merged into a ramp of the disk drive. In particular, the HGAs may include lift tabs that need to be loaded into the ramp and that may be used for sliding on ramp lanes.
One method of loading the lift tabs of the HGAs into the ramp during the disk drive assembly process is by utilizing a comb gripper that rotates the shipping comb and the actuator arms such that the lift tabs and HGAs are loaded into the ramp. However, damage may occur to the HGAs if they are not adequately vertically aligned with the ramp. In particular, collisions may occur between the lift tabs and the HGAs and the ramp during the merge process. For example, the collision may be caused by the lift tab's height traveling lower than it nominal height when the shipping comb first contacts the comb gripper. Existing comb grippers may unfortunately touch the comb tower of the shipping comb at an angle causing angled motion of the shipping comb which results in the tilting of the shipping comp. This tilting may result in the lift tabs and the HGAs being forced downwards such that they may collide with the ramp resulting in a bent lift tab and/or head damage. Unfortunately, once the HGA or lift tab is damaged, the HSA typically needs to be scrapped which may amount to costly yield losses in the disk drive manufacturing process.